Eastern North Pacific Tropical Weather Discussion (Text)

000
AXPZ20 KNHC 091004
TWDEP
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
744 UTC Fri Dec 9 2016
Tropical Weather Discussion for the eastern Pacific Ocean from
the Equator to 32N, east of 140W. The following information is
based on satellite imagery, weather observations, radar, and
meteorological analysis.
Based on 0600 UTC surface analysis and satellite imagery through
0900 UTC.
...SPECIAL FEATURES...
Gulf of Tehuantepec Gale Warning: Satellite winds from around 04
UTC indicated north winds were approaching minimal gale force
over the northern Gulf. Seas will quickly build to 15 ft
downstream of the gulf near 15N95W this afternoon. The gradient
will continue to tighten this evening and tonight as sustained winds
increase to 45 kt. Max seas will build to 16-18 ft by early
Saturday. Gale conditions will persist through sunrise on Sunday,
then pulse to 25-30 kt each night from Sunday night through
Tuesday night.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough axis extends from 10N78W to 07N86W to 07N98W.
The ITCZ continues from 07N98W to 07N107W to 09N113W to 07N119W to
beyond 08N140W. Scattered moderate and isolated strong convection
is present from 06N to 09N between 77W and 82W, as well as from
06N to 11N between 96W and 100W. Scattered moderate convection is
seen from 07N to 11N between 106W and 119W.
...DISCUSSION...
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Gulf of California: Satellite-derived wind data from Thursday
evening showed fresh to strong NW winds over the entire gulf. The
pressure gradient will relax somewhat by this evening with
moderate to fresh NW flow expected over the southern gulf tonight
into early Saturday. As high pressure to the north weakens, gentle
to moderate winds are expected over the Gulf Saturday night
through Thursday.
A ridge extending from 26N120W to 16N103W will shift southwest
Friday. Anticyclonic wind flow around the ridge will become
moderate to fresh west of the Baja Peninsula, and increase to a
locally strong northwest breeze N of 28N within 60 nm of the
coast Saturday night through Monday. Seas in this area will build
to 7-8 ft as winds increase.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Gulf of Papagayo: Fresh to strong offshore winds are developing E
of 88W. Winds will continue to pulse to strong speeds mainly
during the overnight hours this weekend. Seas will top out around
8 ft. A surface trough currently passing south of Hispaniola will
move through the western Caribbean Saturday and Sunday, then cross
Central America early Monday. Model guidance indicates possible
low pressure development along the trough axis as it moves
westward from zones PMZ113 to PMZ111 on Tuesday.
Mostly light to gentle N to NE winds, and combined seas of 2 to 4
ft, are occurring elsewhere N of the monsoon trough, which is
expected to meander between 07N and 10N through Wednesday. Light
to moderate southwest flow is observed from 05N to 09N, with
combined seas of 3 to 5 ft in southwest swell. Moderate to fresh
southerly flow is expected south of 05N through Wednesday.
REMAINDER OF THE AREA...
1027 mb high pressure is centered near 29N125W with a ridge
extending southeast from the high to near 14N103W. A frontal
boundary remains north of the area near 35N. Gentle to moderate
north-northwest flow is expected northeast of the ridge this
weekend and moderate to fresh trades will prevail south of the
ridge and north of the ITCZ. Fresh to occasionally strong NE winds
and combined seas of 8 to 9 ft will generally prevail from 07N to
17N W of 120W north of the ITCZ through Sunday. Low pressure
approaching from the northwest will weaken the ridge on Tuesday
and Wednesday, allowing winds and seas in this area to subside.
$$
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